In a known air outlet for climate control, and described in the German laid-open application OS No. 25 25 196, the air to be admitted to the room travels from a supply channel into a distributor box and passes into the room in a uniform manner through the entire length of the outlet slot of the distribution box. The outlet slot is subdivided into individual ducts each of which contains separately adjustable air guide vanes. The possibility of individually adjusting the air guide vanes of the separate ducts makes it possible to provide for uniform flow of air into the room under varying operational conditions.
The manner in which ventilating air is admitted to a room or other interior space demands advantageously on the type of conditioning that is required. For example, if it is desired to cool a room, it is advantageous to prevent inflow of air into the chamber at angles greater than 45.degree. from the wall so as to avoid unpleasant sensations of cool drafts.
On the other hand, if the space is to be heated, it is more advantageous to inject the warm air substantially perpendicular to the surface of the wall or ceiling of the room so as to insure its proper penetration into the prevailing atmosphere.
Also known in conjunction with modern air conditioning systems is a temperature control based on a change of the admitted air volume that permits an operation with the lowest possible energy losses. In this system, the main channel of the ventilating system is maintained at constant temperature, either on the basis of information regarding the external ambient temperature or regarding the temperature of a control chamber. The constant conduit temperature is chosen to lie in a range extending from the external or control temperature to a value 8.degree. K. below that temperature in the summer time, whereas in the winter season, the range extends from the external temperature or control temperature up to 5.degree. K. above that temperature. The air at this chosen temperature is then supplied to the various spaces to be conditioned through the prevailing air outlets.
During the operation of the system, the thermal load may change, for example because heat-generating machinery is turned off or persons leave the space, causing the temperature of the conditioned space to become too low in the summer time. Conversely, if the thermal load increases, the space would be heated to an excessive temperature in the winter time. To prevent such occurrences, the air volume supplied to the individual spaces through the air outlets is controlled by thermostats and is adapted to the prevailing changes in thermal load. However, these changes in the air volume can be accomplished in the known air outlets having constant exit orifices only with a significant disadvantage. That disadvantage consists of the fact that a decrease in the air volume necessitates a reduction in the velocity of the air jets leaving the orifice. As a consequence, during a cooling process, the air jets tend to bend away from the surface from which they are emerging, in particular the ceiling of the space being conditioned and thus cause the aforementioned undesirable cool drafts. In the heating mode, the lowered air velocity prevents a sufficiently deep penetration of the heated air into the occupied space.